As you have asked about the Reference books for Bank PO exams, check the list below:

Quantitative Aptitude Made Easy by Ramandeep Singh
IBPS - CWE Bank PO/MT (English) 1st Edition - Dr. Meenakshi Upadhyay

BANK PO SOLVED PAPERS For PO & MT - Kiran Prakashan
SBI P.O. Guide 2014 - Shabnam & Prerana Badoni

150+ Solved Papers Bank PO General English - Ajay Singh

Bank Po Quantitative Aptitude Chapterwise Solved Papers 1999-Till Date - Kiran Prakashan
20 Practice Sets IBPS CWE PO/MT Online Exam - V. S. Srivastava
IBPS PO-MT CWE Guide - CBH Editorial Board
101 Speed Tests for IBPS-CWE Bank PO / MT Exam - Disha Experts
Bank Probationary Officers' Exam - V.V.K. Subburaj
Manorma Year Book 2011(for Static GK)
General Knowledge Today (for current affairs)
Marketing Knowledge Dr L.N. Kohli and Shri Prem Kohli

A Modern Approach to Verbal and Non-Verbal Reasoning Dr. R.S.Aggarwal
Quantitative Aptitude for Competitive Examinations Dr. R.S.Aggarwal

General English Dr R.S.Aggarwal
High School English Grammar and Composition Wren and Martin
Quantitative Aptitude for Competitive Examinations Abhijit Guha